The invention relates to a seal for the pipe and base, or floor piece, of mortars or grenade launchers that operate in accordance with the front-loading principle.
Screwing the pipe and base or floor piece together creates an axial prestress force that brings axial annular surfaces into contact with one another, thus producing a seal. An additional copper ring is often used. Mortars that operate in accordance with the front-loading principle are typically placed on the ground for firing. Depending on the ground surface, various types of recoil travel and recoil acceleration may occur. If the ground surface is very soft, the recoil acceleration may cause the forces to be transmitted from the thread to increase to the point that the sealing surfaces separate from one another. The relatively low axial flexibility of the screw connection in particular contributes to this.